|Service|Service ID|Bit rate|Audio channels|Description|Analogue availability|
|---|---|---|---|---|---|
|Capital Yorkshire|C3AA|128 kbit/s|Joint stereo|Dance and R'n'B|105.1 MHz (South & West Yorkshire) 105.6 MHz (Bradford & Sheffield) 105.8 MHz (Humberside)|
|Choice FM|C0CE|128 kbit/s|Joint stereo|R'n'B and Hip-hop|—|
|Heart London|CCCD|128 kbit/s|Joint stereo|Adult contemporary|—|
|Gold|C2CE|64 kbit/s|Mono LSF|Oldies, 60s, 70s, 80s|—|
|Real Radio (Yorkshire)|C3A4|128 kbit/s|Joint stereo|Contemporary|106.2 MHz (South & West Yorkshire) 107.6 MHz (Bradford & Halifax) 107.7 MHz (Sheffield)|
|Real Radio XS|C8C5|128 kbit/s|Joint stereo|Classic rock|—|
|UCB Gospel|CED0|64 kbit/s|Mono LSF|Christian|—|
|UCB Inspirational|CFD0|64 kbit/s|Mono LSF|Christian|—|
|XFM|C0B8|128 kbit/s|Joint stereo|Indie / alternative / rock music|—|
|Yorkshire Radio|CFCD|128 kbit/s|Joint stereo|Pop music and sport|—|
|DAB Guide|E1C000A9|8 kbit/s|Data|Hidden service, EPG data|—|

Question: how many rock stations are listed?
Answer: 2